Counting down to the olympics now terror threats have already dampened the spirit of the game and tonight an ABC news exclusive investigation into dramatic charges of rampant corruption, stories of bribes, suitcases filled with cash and a whistle-blower who claims there is a contract on his life because he dared to speak out. Brian Ross has all the details. Repr: A home at the end of this road, an hour's dry from London, is the hiding place for this exiled Russian businessman Valerie morozov who fears he will be killed after making allegations about payoffs to Russian officials overseeing construction at the winter olympics. That's you will be drowned in blood. Reporter: You'll be drowned in blood. Yes. Reporter: He said he delivered payoffs to some of the officials right inside the office of president Vladimir Putin using a piece of luggage like this stuffed with tens of millions of rubles, a corruption tax he calls it. You have to pay. There is no way out. Reporter: At an estimated cost of between $50 billion to $60 billion, the olympics in sochi will be the most expensive and critics say most corrupt ever. Everybody know this is the most criminal case in the history of Russia. Reporter: Former deputy prime minister Boris nentsov says he has documented how well connected Russians got rich off big olympic construction projects. My estimation they saw about $30 billion altogether. Reporter: They stole? Yeah. Reporter: 30 billion. Yeah. Reporter: He points to the olympic staid yum three times the cost of any previous stadium anywhere in the world. And even worse, he says, the $9 billion highway and rail project to the ski hills above sochi just 30 miles away. The corruption not the concrete making it so expensive he says. In his exclusive interview with ABC news, president Putin said he knew of no evidence of a serious corruption problem. Translator: We have not seen any big large-scale instances of corruption. Reporter: Putin apparently has forgotten about the problems with the long delayed olympic ski slope six times over budget. This remarkable video shows the moment when Putin was told that the contractor building the ski slope was also the very Russian olympic official supposedly overseeing the construction. Translator: So the vice president of the national olympic committee is taking care of such a large-scale construction. Reporter: That official who earned his ire fled the country before he was charged with massive embezzlement. Mr. Putin says he's not aware of any such problems. He's not making any apologies. Thanks very much. Still ahead on "World news," plucked from the sky.

This transcript has been automatically generated and may not be 100% accurate.

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